Analysing GORK clustering for enhanced stomatal control

分析 GORK 聚类以增强气孔控制

• 批准号: BB/M001601/1
• 负责人: Michael Blatt
• 金额: $ 57.06万
• 依托单位: University of Glasgow
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2015
• 资助国家: 英国
• 起止时间: 2015 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=BB%2FM001601%2F1
• 关键词: Analysing; GORK; clustering; enhanced; stomatal

Stomata are pores that provide for gaseous exchange across the impermeable cuticle of plant leaves. They open and close to balance the requirement for CO2 entry for photosynthesis against the need to reduce the transpiration of water vapour and prevent leaf drying. Stomatal transpiration is at the centre of a crisis in water availability and crop production that is expected to unfold over the next 20-30 years: globally, agricultural water usage has increased 6-fold in the past 100 years, twice as fast as the human population, and is projected to double again before 2030. The bulk of water used in agriculture passes through the stomatal pore. Thus stomata represent an important target for manipulating crop performance. Significantly, stomatal responses are often delayed in the face of environmental fluctuations, especially of light. Improving water use efficiency (=amount of carbon fixed in photosynthesis/amount of water transpired) should be possible, without a cost to carbon assimilated in photosynthesis, if the speed of stomatal response can be enhanced.Stomatal movements are driven by solute transport - and consequent uptake/loss of water - across the cell membrane of the guard cells which surround the stomatal pore. Guard cells harbour ion channel proteins to facilitate cation flux for stomatal movement. Uniquely, the opening (or gating) of one class of plant ion channels is also sensitive to external K+ concentration. These channels are found in guard cells of tobacco, Vicia and Arabidopsis, in the latter encoded solely by the GORK gene. Increasing K+ outside moderates channel opening in parallel with the equilibrium voltage for K+ and affects whole-cell conductance. These channels are the main pathway for K+ efflux during stomatal closure, but their K+-sensitivity constrains K+ flux capacity, notably at higher external K+. Estimates based on recent modelling suggests that stomatal closure could be accelerated 3-fold with only a moderate increase in the flux capacity of these channels.The K+-sensitivity of the GORK channel is a property of the channel protein itself, which should facilitate manipulating K+ efflux capacity to accelerate stomatal closure. My laboratory has uncovered evidence that the K+-dependence of GORK gating is associated with its assembly in clusters. These assemblies require the the so-called 'voltage-sensor domains' (VSDs) of GORK to interact with one another. Movement of the VSDs is known to couple voltage to channel gating, so it is likely that interaction between VSDs provides a mechanism for cooperative self-regulation. I propose now to complete the analysis of GORK VSD interaction and the consequences for channel control and for stomatal movements. Regardless of the mechanism, it is clear that these discoveries offer the means to explore a unique and fundamental property of this class of K+ channels in plants and to manipulate channel activity, potentially enhancing the kinetics of stomatal closure and water use by the plant.

气孔是在植物叶片的不渗透角质层上提供气体交换的孔。它们打开和关闭以平衡光合作用对CO2进入的需求，以及减少水蒸气蒸腾和防止叶片干燥的需求。气孔蒸腾作用是水供应和作物生产危机的核心，预计将在未来20-30年内展开：在全球范围内，农业用水量在过去100年中增加了6倍，是人口增长速度的两倍，预计在20 - 30年之前将再翻一番。农业用水的大部分通过气孔。因此，气孔代表了操纵作物性能的重要目标。值得注意的是，气孔反应往往延迟面对环境波动，特别是光。提高水分利用效率（=光合作用中固定的碳量/蒸腾的水量）应该是可能的，而不需要光合作用中同化的碳的成本，如果气孔响应的速度可以提高。气孔运动是由溶质运输驱动的-和随之而来的水的吸收/损失-穿过气孔周围的保卫细胞的细胞膜。保卫细胞的港口离子通道蛋白，以促进阳离子流量气孔运动。独特的是，一类植物离子通道的开放（或门控）也对外部K+浓度敏感。这些通道存在于烟草、野豌豆和拟南芥的保卫细胞中，后者仅由BTK基因编码。增加外部K+会与K+的平衡电压平行地减缓通道开放，并影响全细胞电导。这些通道是气孔关闭过程中K+外流的主要途径，但它们的K+敏感性限制了K+通量的能力，特别是在较高的外部K+。根据最近的建模估计表明，气孔关闭可以加速3倍，只有适度增加这些通道的通量容量。K+-敏感性的EPOK通道是一个属性的通道蛋白本身，这应该有利于操纵K+外流能力，以加速气孔关闭。我的实验室已经发现了证据表明，K+-依赖性的K-MK门控与其组装在集群。这些组件需要所谓的“电压传感器域”（VSD）的PDK相互作用。已知VSD的移动将电压耦合到通道门控，因此VSD之间的相互作用可能提供了协作自调节的机制。我现在建议完成对BMPK VSD相互作用的分析，以及对通道控制和气孔运动的影响。无论机制如何，很明显，这些发现提供了探索植物中这类K+通道的独特和基本性质的手段，并操纵通道活性，从而可能增强植物气孔关闭和水分利用的动力学。

项目成果

New Faces behind the Scenes.

幕后新面孔。

• DOI: 10.1104/pp.18.00140
• 发表时间: 2018
• 期刊: Plant physiology
• 影响因子: 7.4
• 作者: Blatt MR

Evolutionary Conservation of ABA Signaling for Stomatal Closure

气孔关闭 ABA 信号的进化保守

• DOI: 10.1104/pp.16.01848
• 发表时间: 2017-06-01
• 期刊: PLANT PHYSIOLOGY
• 影响因子: 7.4
• 作者: Cai, Shengguan;Chen, Guang;Chen, Zhong-Hua
• 通讯作者: Chen, Zhong-Hua

Plant Physiology Launches Associate Features Editors.

植物生理学推出副专题编辑。

• DOI: 10.1104/pp.18.00113
• 发表时间: 2018
• 期刊: Plant physiology
• 影响因子: 7.4
• 作者: Blatt MR

Light-Driven Chloride Transport Kinetics of Halorhodopsin.

• DOI: 10.1016/j.bpj.2018.06.009
• 发表时间: 2018-07
• 期刊: Biophysical journal
• 影响因子: 3.4
• 作者: Hasin Feroz;Bryan H Ferlez;Cécile Lefoulon;Tingwei Ren;Carol S. Baker;John P. Gajewski;D. J. Lugar;Sandeep Gaudana;P. Butler;Jonas Hühn;M. Lamping;W. Parak;J. Hibberd;C. Kerfeld;N. Smirnoff;M. Blatt;J. Golbeck;Manish Kumar